How can I check if file has been downloaded in ansible

Question

I am downloading the file with wget from ansible.

  - name: Download Solr     shell: wget http://mirror.mel.bkb.net.au/pub/apache/lucene/solr/4.7.0/solr-4.7.0.zip       args:         chdir: {{project_root}}/solr  

but I only want to do that if zip file does not exist in that location. Currently the system is downloading it every time.

Answer 1

Note: this answer covers general question of "How can i check the file existence in ansible", not a specific case of downloading file.

The problems with the previous answers using "command" or "shell" actions is that they won't work in --check mode. Actually, first action will be skipped, and next will error out on "when: solr_exists.rc != 0" condition (due to variable not being defined).

Since Ansible 1.3, there's more direct way to check for file existance - using "stat" module. It of course also works well as "local_action" to check a local file existence:

- local_action: stat path={{secrets_dir}}/secrets.yml   register: secrets_exist  - fail: msg="Production credentials not found"   when: secrets_exist.stat.exists == False 

Answer 2

Unless you have a reason to use wget why not use get_url module. It will check if the file needs to be downloaded.

--- - hosts        : all   gather_facts : no   tasks:    - get_url:        url="http://mirror.mel.bkb.net.au/pub/apache/lucene/solr/4.7.0/solr-4.7.0.zip"        dest="{{project_root}}/solr-4.7.0.zip" 

NOTE: If you put the directory and not the full path in the dest ansible will still download the file to a temporary dir but do an md5 check to decide whether to copy to the dest dir.

And if you need to save state of download you can use:

--- - hosts        : all   gather_facts : no   tasks:    - get_url:        url="http://mirror.mel.bkb.net.au/pub/apache/lucene/solr/4.7.0/solr-4.7.0.zip"        dest="{{project_root}}/solr-4.7.0.zip"      register: get_solr     - debug:         msg="solr was downloaded"      when: get_solr|changed